Fuse plug



July 6, 1937, P. F. DIEFFENBACHER 2,086,406

FUSE PLUG Filed O01). l5, 1936 INVEN-rn ATTORN EY Patented July 6, 1937 UNl'l'E STATES otros PATENT 1 Claim.

This invention relates to fuse plugs and has for the primary object the provision of a device of this character which will indicate clearly to a person when blown and may be cheaply renewed 5 or conditioned icr further use.

With these and other objects in View, this invention consists in certain novel features of conn struction, combination and arrangement oi parts to be hereinafter more fully described and l claimed.

For a complete understanding of my invention, reference is to be had to the following description and accompanying drawing, in which Figure l is a vertical sectional view showing a l fuse plug constructed in accordance with my invention and illustrating the same in an operative condition.

Figure 2 is a view similar to Figure 1 showing the fuse plug when blown.

Figure 3 is a top plan view illustrating the plug.

Figure 4 is a perspective view illustrating a pivotally mounted keeper.

Figure 5 is a plan view illustrating the fuse element.

Figure 6 is a fragmentary side elevation showing means of detachably connecting the cap to the body of the plug.

Referring in detail to the drawing, the numeral l indicates a conventional type of fuse plug body having the usual central Contact 2 and metal screw threaded ierrule 3 forming the other contact of the plug. The body i has the usual chamber l and the contact 2 has a stem 5 extending into the chamber i and terminating in a hook t to engage with a hook 'l of a fuse element t. The hook "i is located at one end of the fuse element while the opposite end is apertured to receive the tree end of a spring arm 9. The spring arm 9 is mounted in a wall of the body l and has one end electrically connected to the errule 3. The 'fuse element 8 when attached to the hook li and to the arm 9 causes the latter to assume a flexed position under tension.

The chamber l of the body l is closed by a removable cap il] having lugs I l to iit in bayonet (Ci. 20G-121) grooves l2 formed in the body whereby a simple turn of the cap in one direction will free the latter from` the body and a turn in an opposite direction will bring about locking of a cap to the body. The cap lil has an opening i3 and pivoted in said opening is a keeper lil, one end oi which is enlarged, as shown at i5, and projects outwardly of the opening i3 and is provided with an opening it. The keeper lll includes the angularly related portions il and i3 and the portion it er;H tends into the chamber il. A signal element iii is secured to the outer surface of the cap and is of resilient formation and may be bent to extend substantially parallel with the cap and engage within the opening l of the keeper thereby retaining thesignal element in non-signaling position. However, when the fuse element 8 burns out the resilient arm El is released engaging the portion it of the keeper and imparting pivotal movement thereto which frees the signal element E9, allowing it to swing outwardly from the cap and assume the position as shown in Figure 2, indicating that the fuse element has blown. Due to the tact that the cap can be easily rem moved from the body the blown fuse element may be removed and a new one substituted in lieu thereof, thereby reconditioning the fuse for further use.

Having described the invention, claim:

A fuse plug including a body having a chamber and a contact extending therein and a threaded ferrule mounted on said body and acting as a second contact, a spring arm electrically connested to the ierrule and extending into the chamber, a fuse element detachably connected y to said arm and to the iirst Contact, a cap detachably connected to the body for closing the chamber and having an opening, a keeper pivoted in said opening, and a spring actuated signal element held in non-signaling position by said keeper and released from said position by the spring arm engaging the keeper when freed of the fuse element due to the latter becoming fused.

PAUL F. DIEFFENBACHER. 

